Examination of the Demagnetization Suppression Effect of Placing Flux Barriers in an IPMSM Using Rare-earth Bonded Magnets

摘要

IPMSM using rare-earth sintered permanent magnets generally have high performance. However, rare-earth sintered magnets are costly, and the stability of the supply of this resource is a concern. In this study, we examine an IPMSM using rare-earth bonded magnets to solve the issue. The use of rare-earth bonded magnets increases the risk of irreversible demagnetization. Therefore, it is necessary to examine the method of demagnetization suppression. In this paper, we design a basic model using rare-earth bonded magnets and evaluate irreversible demagnetization. In addition, we evaluate irreversible demagnetization in the anti-demagnetization models with flux barriers placed at the ends of the magnets. We then analyze the motor characteristics after demagnetization in these models. Finally, based on the obtained results, we examine differences in the demagnetization suppression effect due to the flux barrier shape.